And three of the region's MPs were among the ten biggest claimers in the country. But today they insisted the cost simply reflected the amount of hard work they were doing.

Official figures showed that Redditch Labour MP Jacqui Smith was the third most expensive MP in the Commons. She claimed #158,313 in the last financial year, including #16,548 for postage alone. The money included #21,596 to subsidise accommodation in London and #19,853 for office costs.

The most expensive Birmingham MP was Liam Byrne (Lab Hodge Hill). His claim of #156,988 made him the seventh most expensive MP in the country.

Black Country MP Ian Austin (Lab, Dudley North) came in tenth in the league of big spenders. He claimed #155,242.

All three MPs insisted the cost simply reflected the amount of hard work they put in to serving constituents.

Ms Smith said: "My constituents rightly demand a high level of service, which is why I invest in providing a hard working, constituency based hub for my local casework and campaigning activities."

Mr Byrne said: "Working hard for your constituents does mean writing a lot of letters. It is what I promised to do when I was elected. I notice that if you take out my bill for stamps then I fall to third place in Birmingham and 176th nationally."

Mr Austin said: "Most of this money is used to pay for my office and staff, which is essential in order to serve the people of Dudley."

But they were also defended by the MP with the lowest expenses bill in the region.

David Winnick (Lab, Walsall North) claimed just #80,450. He said: "I'm surprised we call these costs expenses, as they include things like the salary of our secretaries."

The money represented costs MPs had to pay in order to do their jobs, he said.

MPs across the country claimed more than #86 million in expenses and allowances last year, including #3.3 million in the West Midlands. The figures did not include MPs' pensions, which cost a total of #38 million nationally.

Conservative leader David Cameron claimed #135,729 last year and Tony Blair claimed #87,342 in his role as a constituency MP.

The most expensive MP in the UK was Labour's Eric Joyce. The MP for Falkirk in Scotland claimed a total of #174,811.